As far as I'm aware, it seems that Sydney and Blue Mountains have both separated. Interestingly, Perth's operations continue to be operated under the City Sightseeing franchise and has expanded in recent years, also acquiring the Perth Tram Co and their double decker and rebranding that to City Sightseeing. Tram operations are branded differently, but the operation of both the Sightseeing buses and tourist trams come under the same company.

Worldwide, City Sightseeing brand still thrives in many cities, especially some of the recent places I have visited.